[HN Gopher] NASA: Mystery of Life's Handedness Deepens
___________________________________________________________________
NASA: Mystery of Life's Handedness Deepens
Author : bookofjoe
Score : 141 points
Date : 2024-11-22 14:35 UTC (3 days ago)
(HTM) web link (www.nasa.gov)
(TXT) w3m dump (www.nasa.gov)
| robthebrew wrote:
| https://www.nature.com/articles/s41377-020-00367-8
| __MatrixMan__ wrote:
| That's a relevant paper, but this is the one which "deepened"
| the mystery: https://www.nature.com/articles/s41467-024-52362-x
|
| It asserts:
|
| > L-proteins need not emerge from a D-RNA World
|
| So if more than one amino acid chirality could have emerged,
| why did we get the one we got and not several?
|
| From the paper in the parent comment:
|
| > Achiral linearly polarized light interacts with chiral
| objects and their enantiomers differently. An interesting
| example is a light-driven motor. Linearly polarized light can
| rotate a gammadion-shaped gold structure embedded in a silica
| block as a motor.
|
| Imagine you were using some kind of optical tweezers to
| manipulate chiral molecules. I wonder if there's a reason that
| such a device would work better if you had a sample which had
| the same chirality. Suppose so...
|
| If one of your samples made its way to Earth and replicated...
| Well that would be a reason for earth proteins to be biased in
| one direction, despite the laws of physics not prescribing such
| a bias.
| madaxe_again wrote:
| https://en.m.wikipedia.org/wiki/Optical_tweezers
|
| I suppose there's no reason you couldn't use circularly
| polarised light to achieve the effect you're talking about.
| throwawaymaths wrote:
| What is the mystery? Perhaps one handedness was just first by
| chance and won because it self replicated the other handedness
| away by consuming it as food.
| griffzhowl wrote:
| Well, that's the question isn't it? Is it just a frozen
| accident, or is there some nonarbitrary reason for the left-
| handed molecules to be favoured?
| madaxe_again wrote:
| Perhaps aliens eat right handed life, but left handed life is
| poison to them.
|
| Seriously. It would be a pretty good selector, and said
| "alien" need be no more than a snippet of RNA - and it would
| be entirely gone from earth now, eliminated by us sinister
| life forms.
|
| The only evidence would be the ubiquitous absence of
| R-entantiomers in life.
|
| I think I might be lifting from Asimov - _The Left Hand of
| the Electron_.
| Terr_ wrote:
| That kinda kicks the can down the road though, because we
| are faced with almost the same set of questions except
| about the hypothetical alien life.
| throwawaymaths wrote:
| Sure but that might be an unknowable problem. What if the
| difference in likelihood were 60/40.
|
| You could go down all sorts of rabbit holes and none of them
| would truly be falsifiable unless you observed an
| enantiomeric lifeform on some distant planet.
| throwawaymaths wrote:
| (Comsuming enantiomers and pooping out metabolic fragments in
| its native chirality)
| alganet wrote:
| That assumption is even more mysterious.
|
| Why one specific handedness "won"? What caused the other one to
| be food? How can we be sure it was by chance?
|
| Lots of questions.
| throwawaymaths wrote:
| > Why one specific handedness "won"?
|
| Place two competitors at the origin on the number line. On
| any given turn they walk either to the left or to the right,
| with exactly 50% odds of each. First competitor to +100 wins.
|
| > What caused the other one to be food?
|
| Basic chemistry.
|
| > How can we be sure it was by chance?
|
| We can't. If the odds are sufficiently close, we probably
| can't be sure it wasn't chance, either. If we go to space and
| find a planet with life with the other handedness, it was
| probably chance.
| alganet wrote:
| I have so many questions.
|
| How do you know the evolutionary model of these early
| organisms? How do you know that a competition had taken
| place?
|
| If you can't know if it is by chance of not, why
| hypothesize it?
| andrewflnr wrote:
| While all right-handed amino acids would presumably be fine, do
| we have any idea whether mixed chirality would work? I suspect
| no, since they presumably have different folding behavior but
| might be tricky to distinguish chemically during the protein
| synthesis process, making e.g. different codons for left and
| right-handed amino acids infeasible to implement. I'd love to
| hear from a biologist whether any of that is correct.
| fredgrott wrote:
| fun fact some left handed amino acids are poisonous to most
| mammals
| gilleain wrote:
| So a couple of things i remember from back in the old
| structural bioinformatics days...
|
| Firstly, there are naturally occurring mixed-chirality
| (alternating) peptides. They are usually circular iirc.
|
| Secondly, no you can't really have larger proteins with both
| left and right (ignoring glycine). They would not fold into
| nice helix/sheet strucures and likely just be random coil.
|
| For cells to have mixed populations of all-L and all-R proteins
| would mean doubling up all the machinery for creating them.
|
| One theory that I thought was reasonable for why there's a
| monochiral world is that once the arbitrary choice is made (L
| or R) then that gets 'locked in' by all the machinery around
| that choice. As in, L 'won'.
| phkahler wrote:
| >> One theory that I thought was reasonable for why there's a
| monochiral world is that once the arbitrary choice is made (L
| or R) then that gets 'locked in' by all the machinery around
| that choice. As in, L 'won'.
|
| This seems obviously true to me. Mixed doesn't work, so as
| molecules and systems of molecules started replicating one
| chirality won out. It's just chance and there's nothing
| magical about the chirality "chosen" by the process.
| brnaftr361 wrote:
| My initial hypothesis is that there's something present in
| the early stages of life that has a higher energy state
| making it unsustainable for use in a certain conformation and
| so it was nearly immediately selected out.
|
| E.g. a ring structure whose substituents are affected by
| steric hindrance in the left-handed scheme.
|
| And the path of least resistance was just to adapt and build
| around it. Once that precedence was set everything became as
| such. I expect in the earliest stages of life this would have
| been an immense factor as metabolism was not nearly as
| sophisticated as we know it today.
|
| And this selective process may have ocurred well before
| anything we have observed/modeled, and may well be erased.
| Which is to say I agree, but with the caveat that it was a
| substrate-dependent mechanism which selected the downstream
| components rather than random chance.
| gilleain wrote:
| Seems quite possible, but the difficulty would be why one
| enantiomer is less favourable than the other.
|
| Totally agree that it is hard to test these things
| experimentally, or through historical analysis of
| structural remnants. I understand there have been efforts
| to model at a system level these ancient metabolic networks
| but ... then how do you experimentally validate these
| models?
| gus_massa wrote:
| It's a good question, but:
|
| > _might be tricky to distinguish chemically during the protein
| synthesis process_
|
| No, amino acids are bind to tRNA by special proteins that have
| handiness and can easily distinguish the L and R version. Most
| proteins can only operate on one handiness of the target
| molecule.
|
| > _making e.g. different codons for left and right-handed amino
| acids infeasible to implement_
|
| No, there are 64 codons and we are using them to map only 20
| amino acids and a stop signal. So there is a lot of
| duplication. Some bacterias have one or two more amino acids or
| a small tweak in one or two of the conversion table, so it's
| possible to add more stuff there if necessary.
|
| My guess is that mixing L and R amino acid would break
| ribosomes. The ribosomes read the mRNA and pick the correct
| tRNA and connect the amino acid that the tRNA has. I guess that
| the part that makes the connection assumes the correct
| handiness of the amino acids.
|
| Going down the rabbit hole I found
| https://en.wikipedia.org/wiki/Nonribosomal_peptide that
| explains that some peptides (that are like small proteins) are
| formed by special enzymes instead of ribosomes, and some of
| them have D-amino acids or other weirs stuff.
| andrewflnr wrote:
| > No, amino acids are bind to tRNA by special proteins that
| have handiness and can easily distinguish the L and R
| version. Most proteins can only operate on one handiness of
| the target molecule.
|
| Ah, neat. That was the step where I worried about coding
| being infeasible, too, coding for R amino acids wouldn't do
| any good if you couldn't distinguish them. I did know there
| was plenty of room in the encoding scheme.
| westurner wrote:
| From "Amplification of electromagnetic fields by a rotating body"
| https://news.ycombinator.com/item?id=41873531 :
|
| > _ScholarlyArticle: "Amplification of electromagnetic fields by
| a rotating body" (2024)
| https://www.nature.com/articles/s41467-024-49689-w _
|
| >> _Could this be used as an engine of some kind?_
|
| > _What about helical polarization?_
|
| If there is locomotion due to a dynamic between handed molecules
| and, say, helically polarized fields; is such handedness a
| survival selector for life in deep space?
|
| Are chiral molecules more likely to land on earth?
|
| > _" Chiral Colloidal Molecules And Observation of The Propeller
| Effect" https://pmc.ncbi.nlm.nih.gov/articles/PMC3856768/_
|
| > _Sugar molecules are asymmetrical / handed, per 3blue1brown and
| Steve Mould. /?
| https://www.google.com/search?q=Sugar+molecules+are+asymmetr..._
| _https://www.google.com/search?q=Sugar+molecules+are+asymmetr..._
|
| > _Is there a way to get to get the molecular propeller effect
| and thereby molecular locomotion, with molecules that contain
| sugar and a rotating field or a rotating molecule within a
| field?_
| westurner wrote:
| Though, a new and plausible terrestrial origin of life
| hypothesis:
|
| Methane + Gamma radiation => Guanine && Earth thunderstorms =>
| Gamma Radiation
| https://news.ycombinator.com/item?id=42131762#42157208 :
|
| > _A terrestrial life origin hypothesis: gamma radiation
| mutated methane (CH4) into Glycine (the G in ACGT) and then DNA
| and RNA._
| nativeit wrote:
| > "We are analyzing OSIRIS-REx samples for the chirality
| (handedness) of individual amino acids, and in the future,
| samples from Mars will also be tested in laboratories for
| evidence of life including ribozymes and proteins," said Dworkin.
|
| I clicked the hyperlink for OSIRIS-REx samples, and it didn't
| contain any information about what kinds of materials were found,
| but this statement suggests amino acids were collected from
| OSIRIS-REx--did I miss this news? Were there proteins found on an
| asteroid?
| nativeit wrote:
| Indeed I did miss that, what an incredible find, I can't
| believe this never broke through into my routine news feeds!
|
| https://www.hou.usra.edu/meetings/lpsc2024/pdf/1219.pdf
| jebarker wrote:
| How suggestive is this of life elsewhere in the universe?
| staplung wrote:
| On it's own, probably not that much. We know that amino
| acids can form in interstellar space and have in fact
| observed clouds of them in star-forming regions[1]. Finding
| them on a non-planetary object in our own solar system is
| certainly very _cool_ but we already knew they existed in
| _this_ neck of the woods. ;-)
|
| 1: https://www.space.com/amino-acid-tryptophan-perseus-
| molecula...
| jcims wrote:
| Only tangentially related, but because they are so amazing here
| are a few videos that illustrate the process of transcription
| (creating mRNA from DNA) and translation (creating a protein from
| mRNA).
|
| https://www.youtube.com/watch?v=SMtWvDbfHLo
|
| https://www.youtube.com/watch?v=TfYf_rPWUdY
|
| The common complaint with these videos is that everything is more
| complex. One thing that isn't evident is that these specific
| videos (built mostly by Drew Barry) actually model a lot of other
| molecules to create a more realistic physical environment with
| brownian motion and whatnot. Then the irrelevant molecules are
| simply made transparent in the rendering.
|
| Obviously it's still much much more complex (eg the constant
| stream of ATP used to drive many of these operations is not
| illustrated).
|
| There are these and many more great illustrations/explanations at
| WEHImovies on youtube
|
| https://www.youtube.com/@WEHImovies
| divbzero wrote:
| We would be remiss to leave out the 1970s classic _Protein
| Synthesis: An Epic on a Cellular Level_
|
| https://library.ucsd.edu/dc/object/bb90484996
| throwawaymaths wrote:
| these videos are better than most, but are still bad in one
| sense, they really fail to capture just how random walk the
| movements are. For example, in the first video the script says
| "a mediator protein complex arrives" as if it is directed there
| by some sort of orchestration agent. It's not. It's more like
| "a mediator protein complex drunkenly stumbles in and connects
| after a few thousand misses". Of course it's hard to make that
| into a captivating video.
|
| As I said, the WEHI movies are pretty good in that at least
| they add some random walk into the motions. There was a harvard
| artist-professor (can't remember who) who literally made videos
| with exact parabolic and helical trajectories and then was
| crowing about how beautiful the biological system is.
| mongol wrote:
| Thank you for clarifying what I have wondered. In most of
| these videos it appears as if the molecules have an intent
| and act on a plan. It makes me think "how do they know to do
| that".
| Mistletoe wrote:
| https://www.smithsonianmag.com/space/must-all-molecules-life...
|
| More explanation here.
|
| >Oftentimes both the left- and right-handed versions of, for
| example, an amino acid, were found in equal amounts--exactly what
| might be expected. But in many cases, one or more organic
| molecule was found with an excess of one hand, sometimes a very
| large excess. In each of those cases, and in every meteorite
| studied so far by other researchers in the field, the molecule in
| excess was the left-handed amino acid that is found exclusively
| in life on Earth.
| polishdude20 wrote:
| Could these asteroids be from when the moon was created?
| skykooler wrote:
| The moon was created far before life formed - the best
| estimates put its formation about 4.5 billion years ago,
| while life didn't form until 3.7 billion years ago. So any
| complex molecules from that process would not be present on
| asteroids of lunar origin.
| gcanyon wrote:
| For a really brilliant visualization of the time scale, I
| can't recommend this Kurzgesagt video highly enough. It's
| an animation of the condition of the entire history of the
| Earth, at 1.5 million years per second of video.
| https://www.youtube.com/watch?v=S7TUe5w6RHo
| singularity2001 wrote:
| >> The moon was created far before life formed
|
| not in the panspermia theory
| nkrisc wrote:
| A better way to put it might be that current lineages of
| life on Earth arose after the moon was created - the
| assumption being any life that arose before the moon was
| created would not have survived a fully molten Earth.
| rybosome wrote:
| Perhaps debris from an asteroid impact.
| mannyv wrote:
| Isn't it the same reason that the right hand rule works?
| hydrolox wrote:
| Right hand rule is just an arbitrary decision defining
| counterclockwise to be positive, but I guess it's true that it
| could be "less arbitrary" if certain things are more
| counterclockwise than clockwise
| hoc wrote:
| Waiting for the
|
| Creator -> left-handed
|
| conclusion...
| divbzero wrote:
| > _"The findings suggest that life's eventual homochirality might
| not be a result of chemical determinism but could have emerged
| through later evolutionary pressures."_
|
| Homochirality resulting from chemical determinism would be the
| more surprising result to me.
|
| The straightforward explanation is that random perturbations
| early in the evolution of life broke symmetry and led to
| homochirality of all descendent life, similar to how random
| perturbations early in the life of the universe broke symmetry
| and led to our world being made of particles instead of
| antiparticles.
| andrewflnr wrote:
| It's still not obvious how they could be separated at all by
| pre-biotic processes. You need to go from (in principle anyway)
| a pretty well-mixed 50-50 mixture to basically only lefties. I
| believe this is still one of the bigger problems for
| abiogenesis, and frankly I think you're being too glib about
| the antimatter problem too. I expect we're eventually going to
| find out about specific mechanisms that cause those.
| anlsh wrote:
| A very plausible explanation is that the separation was
| biotic
| andrewflnr wrote:
| There's a bootstrapping problem, though.
| JackFr wrote:
| >The straightforward explanation is that random perturbations
| early in the evolution of life broke symmetry and led to
| homochirality of all descendent life, similar to how random
| perturbations early in the life of the universe broke symmetry
| and led to our world being made of particles instead of
| antiparticles.
|
| Straightforward (and plausible) are not the same as true.
| Random perturbations are a parsimonious explanation, but a
| deeply unsatisfying one. With respect to matter vs antimatter,
| my understanding is that this remains an open research question
| in physics.
| theodorejb wrote:
| What evidence would it take for more scientists to recognize that
| perhaps life didn't evolve through some evolutionary process, but
| was intentionally created? It seems like few ever consider that
| their starting presupposition may be wrong.
| scrapcode wrote:
| I certainly am trending that way as I grow older. As I've
| recently started to re-dive into Christian theology, the fine-
| tuning argument seems more and more interesting, and it's
| pretty difficult to find "good" secular arguments against it.
| Terr_ wrote:
| I don't know, I think the arthropic principle is still going
| really strong: It's like this because if it wasn't we would
| be asking different questions or not around to ask at all.
|
| It's hard to consider something "so improbable that it must
| have been God" when we look out at a universe so
| incomprehensibly bigger that the real question becomes why we
| haven't evidence of it happening _more._
| cowl wrote:
| Anthropic principle is the most useless of all and it's
| used to avoid explanation instead of trying to find one.
| Imagine Newton answering to why objects fall with "because
| if they did not we would be asking different questions"...
| what a great advance for humanity /s
| recursive wrote:
| I don't think your fictional Newton is really invoking
| the anthropic principle.
|
| In all the zillions of galaxies that exist, the ones
| where intelligent life developed are more likely to be
| observed by intelligent life. Therefore, intelligent life
| can't make any arguments based on probability that
| intelligent life developed, because our observation of
| the phenomenon is not independent.
|
| And maybe some people have used it to avoid explanation,
| but it also doesn't really conflict with any effort to
| explain either.
| cowl wrote:
| more likely or less likely has nothing to do with
| observation indipendece. I flip a weighted coin and it's
| tails 99% of the time, it's the coin that is weighted it
| has nothing to do with me. The same thing with the
| parameters of the universe, the fact that life is present
| on Earth and not on Mercury (to take an exterme example)
| is not dependent on the observer being intelligent or
| even alive. even a non intelligent "aparatus" can detect
| it. it may not "know" to clasify it as life/not life but
| it can detect the difference.
|
| Saying that we wouldn't be here to ask the question is
| not an answer to anything because we are here and we need
| to understand how and why.
| recursive wrote:
| I think we are vigorously agreeing with each other.
| Terr_ wrote:
| You're confusing two different kinds of question:
|
| 1. "What the mechanisms or rules that explain or seem to
| govern this observable phenomenon?"
|
| 2. "The rules behind our own existence seem unique or
| low-probability, can I use our N=1 sample to safely
| assume we are _inherently_ special and /or the existence
| of a god?"
| cowl wrote:
| Those are the same kind of question. take god or the
| "special" out of the second one and you will see that is
| only that part that most react against. Noone reacts with
| the antropic principle to the Fermi's paradox, noone even
| reacted with it to the simulation hypotheses that in my
| view is for all intents and purposes the religious one.
| but only because it did not contain, by Name, the God, it
| is acceptable.
| philsnow wrote:
| I know it was just a typo but "arthropic principle" sounds
| like something from A Deepness in the Sky
| Terr_ wrote:
| That would dovetail with:
| https://en.wikipedia.org/wiki/Carcinisation
| beltsazar wrote:
| The anthropic principle is ridiculous. Suppose that,
| against all odds, you survive the worst plane crash in
| history. Then you ask NTSB what caused the crash and why
| you survived. They answer:
|
| "Nonsense! You wouldn't have asked the questions if you
| hadn't survived."
|
| Questions stand alone, regardless of whether someone or
| something exists to ask them.
| AnimalMuppet wrote:
| As it's often used, the anthropic principle is fatally
| flawed.
|
| It often starts with an argument between a creationist
| (could also be an advocate of intelligent design, but I'll
| just call them the creationist) and an evolutionist. The
| creationist says, look, the origin of life by purely
| naturalistic means is ridiculously improbable (and
| therefore it's reasonable to consider the possibility that
| God did it). They trot out some generally-accepted
| scientific principle, do a back-of-the-envelope
| calculation, and come up with a number that is, in fact,
| ridiculously improbable.
|
| The evolutionist responds with the anthropic principle - if
| no life had arisen in this universe, we would not be here
| arguing about how life arose. This is clearly logically
| correct. It is also completely irrelevant.
|
| The creationist didn't argue that life couldn't have arisen
| in this universe. They argued that it could not have arisen
| _by purely naturalistic means_. They 're arguing about
| _how_ , not about _whether_. The creationist might answer:
| "Yes, I agree that if life had not arisen in this universe,
| _either by creation or by naturalistic processes_ , then we
| would not be here having this conversation. But the
| question is, _which_ way did life begin? " The anthropic
| principle doesn't address that issue whatsoever.
|
| It doesn't address that issue _unless_ you add an
| assumption - that life _had_ to begin by purely
| naturalistic means, that is, that the probability of
| creation is precisely zero. Then the anthropic principle is
| relevant, but then there 's a new issue, that of begging
| the question.
|
| I suspect that this assumption is present on the side of
| everyone on the evolution side that pulls out the anthropic
| principle in an argument with a creationist, but I have
| _never_ heard it explicitly stated. I 'm not even sure the
| evolutionist realizes they're making an assumption - it's
| so ingrained in their world view that they can't think that
| the alternative might be possible.
|
| I grant you that the universe is huge and the evidence
| available is small. But that can turn into an "evolution of
| the gaps" argument quite easily, so I'm not sure you want
| to seriously use it.
| roncesvalles wrote:
| Aside from the mountain of actual evidence, just to build a
| philosophical intuition against fine-tuning - you need to
| appreciate the enormous scale of trial and error at play.
|
| - The Earth seems like the perfect planet but looking out
| into the sky there are trillions of planets that aren't
| perfect at all.
|
| - Most likely the universe also appears "perfect" for the
| same reason - there must be a graveyard of universes where
| the parameters just didn't work out for life.
|
| - Evolution is much the same - many mutations occur all the
| time, most are fixed by cellular machinery, most that aren't
| are deleterious, but once in a while a helpful mutation
| emerges. Take a moment to understand the timescale involved.
| Don't just handwave away 3.8 billion years as some number -
| _feel_ it, starting at 1 year and stepping up each order of
| magnitude. You will realize that a million years is
| essentially "forever ago", and we had 3800 of those to get
| here. Consider how many species exist that aren't
| civilizational sentient intelligence.
| myflash13 wrote:
| You're misunderstanding the point about fine-tuning
| entirely. It doesn't matter how many billions of years it
| took, if some of the parameters of fundamental physics were
| slightly different, even trillions of years would've
| resulted in nothing.
| beltsazar wrote:
| Fine tuning for the earth might be able to be explained
| away most easily, like you said. Fine tuning for the
| universe, though...
|
| Firstly, we have zero evidence for multiverse. Some
| scientists even argue that the idea is untestable and
| unfalsifiable.
|
| When you said:
|
| > there must be a graveyard of universes where the
| parameters just didn't work out for life
|
| You just committed inverse gambler's fallacy. It's like:
|
| > You wake up with amnesia, with no clue as to how you got
| where you are. In front of you is a monkey bashing away on
| a typewriter, writing perfect English. This clearly
| requires explanation. You might think: "Maybe I'm dreaming
| ... maybe this is a trained monkey ... maybe it's a robot."
| What you would not think is "There must be lots of other
| monkeys around here, mostly writing nonsense." You wouldn't
| think this because what needs explaining is why this monkey
| --the only one you've actually observed--is writing
| English, and postulating other monkeys doesn't explain what
| this monkey is doing.
|
| -- https://www.scientificamerican.com/article/our-
| improbable-ex...
| IAmGraydon wrote:
| I know I really shouldn't take this bait, but...no one has
| proof either way. That said, we have a massive amount of
| scientific evidence that shows it could have naturally evolved
| and zero evidence that something created us. Finding something
| that we don't understand doesn't mean we have evidence of
| creation. Ancient civilizations believed that rain came from
| the gods because they were unaware of how weather combines with
| the phases of matter and creates atmospheric condensation.
|
| That being the state of things at the moment, I lean towards
| the evidence. Also, this is a scientific oriented discussion
| forum, so you must expect that many people here are going to
| disagree with you. Could you be correct? Sure, but we just
| don't have reason to believe that at this point.
| luqtas wrote:
| yeah but what if the creators of life orchestrate the
| condensation? /s
|
| the amount of text (considering this is a hardware/software
| community) i read here defending psychoanalys/acupuncture &
| the likes as well some opinions on ecology/nutrition makes me
| pretty agnostic of scientific orientation from users... we
| are (most of the times) just a bunch of laypersons often only
| reading titles & conclusions of most papers we read
| myflash13 wrote:
| > we have a massive amount of scientific evidence that shows
| it could have naturally evolved
|
| Define "naturally". However you define it, that is precisely
| what some people call "divinely".
| photonthug wrote:
| For better or worse the standard of evidence for almost
| everything is more like "smoking gun" than "I found a bullet".
| In some cases this is bad, in others it is good. Just consider
| all the criminal matters where the crime is only a crime if you
| can additionally demonstrate intent, which is strange right,
| since it doesn't change outcomes / injuries at all. Since
| sufficiently ancient guns won't even be smoking anymore this
| will be problematic for creationists even if they are correct,
| so I think we'd need a new kind of burning bush.
| andrewflnr wrote:
| Enough evidence to overcome the enormous pile of evidence that
| life evolved over billions of years. Often literal piles, in
| the case of geology, but there's a lot of different kinds of
| interlocking evidence that suggest a pretty clear picture, even
| if a few puzzle pieces are still missing.
|
| Unless you're thinking of panspermia, in which case most any
| hard evidence would do. But that doesn't really sound like your
| thing.
|
| - a former creationist
| myflash13 wrote:
| It's not just that a few puzzle pieces are missing.
| Abiogenesis is entirely unproven and nobody has a clue how it
| works and nobody can demonstrate experimentally any of the
| hypothetical mechanisms.
| andrewflnr wrote:
| No, that actually is still "a few puzzle" pieces compared
| to the entirety of the geologic record, relatively clear
| progressions of life forms over time that broadly line up
| with physical and genetic taxonomy. There are some gaps,
| yeah, but enough to clearly imply that the overall picture
| is correct.
|
| By contrast, the epistemological picture for creationism is
| a trash fire. It requires an ever increasing amount of
| special pleading to explain all the other evidence. And you
| don't get to complain that "abiogenesis is entirely
| unproven", about an event that necessarily happened long
| before recorded history under entirely different
| conditions, unless your own theory can stand up to a higher
| standard of evidence. Which it can't. Speaking, again, as
| someone who grew up under creationism and had to lever
| myself out of it piece by piece of evidence.
|
| (Oh, and if you think "nobody has a clue" how abiogenesis
| worked, you're out of date. Try reading about the work of
| Nick Lane and Jeremy England, IIRC.)
| myflash13 wrote:
| You don't get to claim that an "event happened long
| before recorded history under entirely different
| conditions", because anyone can make that claim. That's
| not science, not evidence. I can claim the same thing for
| intentional creation, for example.
|
| If anybody has a clue how abiogenesis works, then they
| should prove it by doing it. Manufacture some bacteria
| out of sand. Claiming "it takes a trillion years of
| primordial soup" is an another wild unsubstantiated claim
| that anyone can make. That's the same thing as saying:
| "wait a few centuries and God will show you."
|
| By the way, evidence for natural evolution does not
| contradict creationism, because God could've created some
| things through a process of natural evolution -- it's a
| false dichotomy to assume that evidence for evolution is
| evidence against creationism; it's not. Whether or not
| natural evolution happened is tangential to the claim of
| creationism.
|
| The epistemological picture for creation is quite sound.
| Fermi's paradox is clear evidence we're special.
| Logically, we can define God as existence itself, and the
| existence of "anything" is proof of Him. It simply can't
| be any other way. The fact that we have intentionality is
| also proof that intentionality "exists" and that in turn
| is proof that Existence is intentional.
| bediger4000 wrote:
| If we decided that life had been deliberately created, we could
| get some insight into the god or gods who did it. What kind of
| a diety creates parasites, for example. What kind of pantheon
| creates a universe with Goedel's Incompleteness built in, or
| the difficulty of the Busy Beaver game?
|
| Those are fun questions.
| beambot wrote:
| Sounds a bit like playing with ice-nine...
|
| https://en.m.wikipedia.org/wiki/Ice-nine
___________________________________________________________________
(page generated 2024-11-25 23:01 UTC)